Intraocular pressure-reducing effects and safety of latanoprost versus timolol in patients with chronic angle-closure glaucoma

Abstract

Objective: To demonstrate that the intraocular pressure (IOP)-reducing effect of latanoprost once daily is at least as good as that of timolol twice daily in patients with chronic angle-closure glaucoma (CACG). Design: Randomized, double-masked, multicenter 12-week study. Participants: In all, 137 patients with unilateral or bilateral CACG were treated with latanoprost, and 138 were treated with timolol. Methods: Patients received either latanoprost (9 PM) and a placebo (9 AM) or timolol (both 9 AM and 9 PM). Intraocular pressure was measured at 9 AM and 5 PM at baseline and weeks 2, 6, and 12. Main Outcome Measures: The difference between groups in daily IOP (average of 9 AM and 5 PM measures) reduction was the primary outcome. Secondary outcomes included differences between groups in IOP reductions at 9 AM and 5 PM, and in proportions of patients reaching specified daily IOP levels. Results: Using repeated measures (analysis of covariance: intent to treat), mean changes from baseline in daily IOP levels during 12 weeks were -8.2 mmHg and -5.2 mmHg for latanoprost- and timolol-treated patients, respectively (difference: -3.0 mmHg [95% confidence interval: -4.0, -2.1], P<0.001). Greater reductions in IOP levels at both 9 AM and 5 PM were found in latanoprost-treated patients (P<0.001 for both), and greater proportions of patients receiving latanoprost reached prespecified target daily IOP levels (P<0.001 for all 3 target levels tested). Both drugs were well tolerated. Conclusion: Latanoprost administered once daily provides significantly greater IOP reduction in CACG patients than does timolol instilled twice daily. © 2004 by the American Academy of Ophthalmology.